Valve assembly

ABSTRACT

A valve assembly ( 10 ) able to be mounted with a liquid container, the valve assembly comprising: a housing ( 20 ) having a passageway ( 60 ) that extends through the housing; a breather float valve ( 80 ) mounted within the housing, the breather float valve movable between an open position to allow gas to pass through the passageway and a closed position that prevents liquid from passing through the passageway; a liquid inlet ( 30 ), forming part of the housing, the liquid inlet allowing fluid to pass into the housing; and an inlet float valve ( 41 ) mounted within the housing, the inlet float valve movable between an open position that permits the flow of liquid through the liquid inlet and a closed position that prevents the flow of fluid through the liquid inlet.

FIELD OF THE INVENTION

This invention relates to a valve assembly. In particular, the inventionrelates to a valve assembly used to protect fuel tanks from beingoverfilled with fuel and therefore the invention will be described inthis context. However, it is envisaged that the valve assembly may beused to protect the other types of containers from being overfilled withother types of fluid.

BACKGROUND OF THE INVENTION

For many years large machinery fitted with fuel tanks have been equippedwith fast fill systems to enable rapid filing of large capacity fueltanks. The existing fast fill fuel systems rely on an air vent thatprevents air from escaping the fuel tank when the required level of fuelhas been attained. This causes pressure in the fuel tank to increase toa level that automatic shuts-off a fuel supply nozzle.

A major concern of this system is that when the fuel level activates theshut-off for the fuel supply nozzle, the shut-off can be overridden andfuel can continue to be forced into the fuel tank above the normallevel. This can cause the fuel tank to rupture from the high pressureattained when filling.

U.S. Pat. No. 6,311,723, (by the applicant), has addressed this problemby devising a flow control valve assembly that prevents the build up ofpressure within the fuel tank during and after filing. The flow controlvalve assembly also prevents the supply fuel nozzle from beingoverridden thus preventing the possibility of overfilling. U.S. Pat. No.6,311,723 is hereby incorporated by reference.

The control valve assembly of U.S. Pat. No. 6,311,723 uses float valveto determine when the level of fuel in the fuel tank is at a desiredlevel. When the desired level of fuel has been attained, the float valveis used to block the flow of fuel through a bleed pipe to stop the flowof fuel through a control valve. An open breather is provided within thefuel tank to allow gas to escape from the fuel tank during filling toprevent the fuel tank rupturing.

The flow control valve assembly operates very effectively on machinerythat is predominately stationary. However, when the control valveassembly is mounted to vehicles' fuel tanks, such as those located intrucks and excavators, some difficulties may experienced during movementof the vehicle.

One problem that may be experience is that the float valve may becomebroken. The float valve comprises a float that is mounted on a pivotallymovable elongate arm. This arm can break due to the large forces thatare exerted on the arm by the surging fuel caused by movement of thevehicle.

In the event that the control valve assembly fails, in this or any othermanner, the fuel supply nozzle will continue to fill the tank and passfuel through the open breather until the nozzle is shut-off manually.This may lead to many hundreds or even thousands of litres of fuel beingwasted and the spilt fuel being disposed.

Another problem that occurs is fuel is passed through the open breatherduring movement of the vehicle. Fuel surges cause fuel to flow throughthe open breather and escape the fuel tank. Again, this wastes fuel andis environmentally unfriendly. Further, the spilt fuel also creates afire vehicle hazard.

OBJECT OF THE INVENTION

It is an object of the invention to overcome or alleviate one or more ofthe above disadvantages or to provide the consumer with a useful orcommercial choice.

SUMMARY OF THE INVENTION

In one form, although not necessarily the only or broadest form, theinvention resides in a valve assembly able to be mounted with a liquidcontainer, the valve assembly comprising:

a housing having a passageway that extends through the housing;

a breather float valve mounted within the housing, the breather floatvalve movable between an open position to allow gas to pass through thepassageway and a closed position that prevents liquid from passingthrough the passageway;

an liquid inlet, forming part of the housing, the liquid inlet allowingfluid to pass into the housing; and

an inlet float valve mounted within the housing, the inlet float valvemovable between an open position that permits the flow of liquid throughthe liquid inlet and a closed position that prevents the flow of fluidthrough the liquid inlet.

Preferably, the valve assembly also includes a relief valve that ismovable between an open position and a closed position to allow pressureto be relieved from the container.

Preferably, the housing is cylindrical.

Preferably, the float valve includes a float and a stem. A valve sealmay be located adjacent the end of the stem.

Preferably, a fuel chamber is located adjacent the inlet in which fuelis passed. A shelter may be provided within the fuel chamber in which anend of the stem is located when the float valve assembly is in the openposition

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiment of the invention will be described with reference to theaccompanying drawings in which:

FIG. 1 is a section side view of a valve assembly with a breather floatvalve and an inlet float valve in an open position according to a firstembodiment of the invention;

FIG. 2 is a section side view of the valve assembly of FIG. 1 with thebreather float valve and the inlet float valve in a closed position; and

FIG. 3 is a section side view of the valve assembly of FIG. 1 with arelief valve in an open position.

FIG. 4 is a sectional side view of the valve assembly of with a breatherfloat valve in an open position according to a second embodiment of theinvention;

FIG. 5 is a sectional side view if the valve assembly of FIG. 4 with abreather float valve in a closed position; and

FIG. 6 is a schematic representation of the valve assembly connected toa control valve.

DETAILED DESCRIPTION OF THE PREFFERRED EMBODIMENT

FIG. 1 shows a valve assembly 10 that is primarily used in a fuel tank1. The valve assembly 10 is normally used in conjunction with a controlvalve 2, as described in U.S. Pat. No. 6,311,723, to prevent fuel fromentering the fuel tank when the fuel tank has reached a predeterminedlevel. FIG. 6 shows the valve assembly 10 connected to the control valve2 via a bleed pipe 3. The control valve 2 is connected to a fuel pump 4and supply tank 5.

The valve assembly 10 comprises a housing 20 that is hollow andsubstantially cylindrical in shape. The housing 20 has several fuelholes 21 located along its length that allow fuel located within thefuel tank to pass in and out of the housing 20.

An inlet 30 is provided at a lower end of the housing 20 through whichpasses fuel. The inlet 30 is fluidly connected to two separate screwthreaded apertures 31 and 32. The bleed pipe 3 is connected to one ofthe apertures 31 or 32. The bleed pipe is fluidly connected to thecontrol valve to activate the control valve as disclosed in U.S. Pat.No. 6,311,723. The screw-threaded apertures 31 and 32 allow the bleedpipe to be connected outside or inside the fuel tank.

An inlet float valve 40 is housed in a lower end of the housing 20. Theinlet float valve 40 is formed from a inlet float 41 and stem 42. Avalve seal 43 is located adjacent the end of the stem 42 for sealing theinlet 30.

The inlet float valve 40 is mounted within the housing so that the stem42 can reciprocate between an open position, in which fuel is able topass through the bleed pipe 3 and through the inlet 30 into the fueltank 1, and a closed position that prevents the flow of fuel through theinlet.

A fuel chamber 50 is located between the inlet 30 and the apertures 31and 32. The fuel chamber 50 provides a shelter 51 in which an end of thestem 42 is located when the inlet float valve 40 is in the openposition.

The top of the housing 20 is open so that a passageway 60 is providedbetween the inside and outside of the fuel tank. This allows gas to passfrom within the fuel tank to the atmosphere so that the fuel tank doesnot rupture during filling of the fuel tank. A relief plate 71 ispositioned within an upper end of the housing 20. Breather holes 72 arelocated within the relief plate 71. The breather holes 72 form part ofthe passageway 60.

A breather float valve 80 is provided adjacent the breather holes. Thebreather float valve 80 is formed from a breather float 81 and a rod 82.A platform 83 and the relief plate 71 guide rod 82. The float 81 is ableto reciprocate along the length of the rod 82 between the relief plate71 and the platform 83. The rod 82 is fixed to the float 81 withcirclips.

The breather float valve 80 is in an open position when the breatherfloat 81 is located adjacent the platform 83 and gas is free to passthrough the breather holes 72. The breather float valve 80 is in aclosed position when the breather float 81 is located over the breatherholes 72 and fuel cannot pass through the breather holes 72.

A relief valve 70 is formed adjacent a top end of the housing 20. Therelief valve 70 is formed from the relief plate 71, a spring 73 and acap 74. The relief plate is able to move within a skirt 22 formed at thetop of the housing 20. The skirt 22 has a number of circumferentiallyspaced relief holes 23. The spring 73 holds the relief plate at the baseof the skirt 22. The spring 73 is held in position by a cap 74 that islocated over the housing 20.

In use, the valve assembly 10 has a number of functions. In a fuellingnormal operation, the inlet float valve 40 is in the open position suchthat the stem 42 sits within the shelter 51 as shown in FIG. 1. Thebleed pipe 3 passes fuel in to the fuel chamber 50. The fuel then passesthrough the inlet 30, into the housing 20 and out the fuel holes 21 intothe fuel tank. Any turbulence that is created by the fuel passingthrough the fuel chamber 50 does effect the valve seal 43 as it islocated within the shelter 51.

As the fuel tank fills with fuel, the passageway 60 of the housing 20also fills with fuel to the same level. The inlet float 41 rises withinthe housing until the valve seal 43 blocks the inlet 30 as shown in FIG.2. The pressure of the fuel within the bleed pipe, as well as the fuelwithin the tank acting on float, maintains the valve seal 43 in positionwithin the inlet 30. Once the inlet 30 is blocked, the bleed pipe 3fills with fuel causing the control valve 2 to become closed andprevents further filling of the fuel tank.

When the vehicle is moving, the housing 20 prevents damage of the inletfloat valve 40. The impact forces created by surging fuel within thefuel tank impact the housing 20 not the inlet float valve 40.

However, the surging fuel can still extend up passageway 60 and up tothe breather holes 72. The breather float valve 80 prevents this surgingfuel from escaping through the breather holes 72 as the breather float81 moves with the surging fuel blocking the breather holes 72 as shownin FIG. 2.

The breather float valve 80 also provides a fail safe during fuelling ofthe fuel tank. If the bleed pipe 3 is severed or the control valve failsor the inlet float valve fails, then a fuel supply nozzle (not shown)will continue to pump fuel into the fuel tank. The fuel tank will fillwith fuel until the breather float 81 moves to the closed position toblock the breather holes 72. The continued fuelling of the fuel tankcreates pressure within the fuel tank. When the fuel tank reaches a fuelnozzle shut off pressure, then the fuel supply nozzle will shutoffstopping the fuel tank from rupturing.

If the fuel supply nozzle does not shut off automatically due to amechanical fault, then the fuel supply nozzle will continue to supplyfuel to the fuel tank. This causes the pressure within the fuel tank toincrease. At a pressure less than the rupture pressure of the tank, thepressure relief valve is opened as shown in FIG. 3. This occurs when thefuel tank pressure becomes greater than the spring pressure causing therelief plate 71 to move upwardly until it passes over the relief holes23 in skirt 22. Fuel then passes from the tank, through the relief holes23, into the cap 74 and through a cap hole 75. The fuel flowing from thecap 74 will indicate to an operator to shut the fuel supply nozzle offmanually.

FIG. 4 and FIG. 5 show a second embodiment of a valve assembly 10. Inthis embodiment, a breather float valve spring 84 is mounted around therod 82 on the modified platform 83 below the breather float 81. Thebreather float valve spring 84 engages the breather float 81.

The breather float valve spring 84 assists in moving the breather float81 to the closed position in the event of a vehicle roll over. Thebreather float 81 is of sufficient weight to compress the breather floatvalve spring 84 when the valve assembly is in a substantially verticalposition. However, during a roll over, less force is applied by thebreather float 81 on the breather float valve spring 84 when the valveassembly 10 moves from a substantially vertical position to asubstantially horizontal position. Therefore, the breather float valvespring 84 causes the breather float 81 to move to the closed position sothat fuel cannot escape from the tank through the breather holes 72 inthe event of a vehicle roll over.

The valve assemble provides a number of advantages. Firstly, the valveassembly is not damaged by surging fuel making the valve assemblysuitable for use in vehicles. Secondly, the breather float valveprevents fuel from escaping the valve assembly when the fuel surgeswithin the fuel tank during movement of the vehicle. Thirdly, in theevent of failure of the inlet float valve, control valve or bleed pipe,the breather float valve prevents the loss of fuel by blocking thebreather holes causing pressure build up within the fuel tank and thuscausing the fuel supply nozzle to shut off. Lastly, the pressure reliefvalve prevents the fuel tank from rupturing from over pressurising ofthe fuel tank.

The valve assembly can be easily retro fitted or fitted into existingtanks. It is sized to fit into holes that are located in tanks forexisting systems.

It should be appreciated that various other changes and modificationsmay be made to the embodiment described without departing from thespirit or scope of the invention.

1. A valve assembly able to be mounted with a liquid container, thevalve assembly comprising: a housing having a passageway that extendsthrough the housing; a breather float valve mounted within the housing,the breather float valve movable between an open position to allow gasto pass through the passageway and a closed position that preventsliquid from passing through the passageway; an liquid inlet, formingpart of the housing, the liquid inlet allowing fluid to pass into thehousing; and an inlet float valve mounted within the housing, the inletfloat valve movable between an open position that permits the flow ofliquid through the liquid inlet and a closed position that prevents theflow of liquid through the liquid inlet.
 2. The valve assembly of claim1 wherein the valve assembly includes a relief valve that is movablebetween an open position and a closed position to allow pressure to berelieved from the container.
 3. The valve assembly of claim 1 whereinthe housing is cylindrical.
 4. The valve assembly of claim 1 whereininlet float valve includes a float and a stem.
 5. The valve assembly ofclaim 4 wherein a valve seal is located adjacent the end of the stem. 6.The valve assembly of claim 5 wherein a fuel chamber is located adjacentthe liquid inlet in which fuel is passed.
 7. The valve assembly of claim6 wherein a shelter is provided within the fuel chamber in which an endof the stem is located when the float valve assembly is in the openposition.
 8. The valve assembly of claim 1 wherein the breather floatvalve includes a rod and breather float.
 9. The valves assembly of claim8 wherein a spring engages the breather float valve.
 10. The valveassembly of claim 2 wherein the relief valve includes a relief plate, aspring and a cap.